Lecture 2- Evolution and HIV
General global distribution of HIV infections.
- 35 million people currently living with HIV
- In Canada this comes to 1.5% of our population whereas in Africa it is about 15 to
Reasons why HIV is more common in some parts of the world than others.
- much more common in Africa because of the lower standard of living, fact that it
can be passed through animals that originated in Africa
- SIV virus jumped from chimpanzees – this jump is known as zoonosis
Factors that explain why no cure or universal vaccine has been developed for
- the virus mutates very quickly and as a result it is hard to keep track of its many
Reasons why viruses are not considered “alive”.
- viruses are not considered alive because don’t fit into the tree of life
- they simply do not exist if they have no host cell
- they have genetic information (DNA, RNA) but have no metabolism of their own
- much debate still though as to if we can consider them “living”
Reasons why anti-viral drug therapies often have serious side effects.
- anti- viral drugs have serious side-effects because there are no specialized steps
that these drugs can do to target only infected cells
- as a result the drugs will target cells that are not infected as well
Major steps in life cycle of HIV.
- Virion (viral particle) enters host cell
- Reverse transcriptase converts RNA to viral DNA (no proof reading)
- Integrase splices viral DNA into host DNA
- Transcription and translation occur and new virions assemble and enter
- Immune system collapses
Specific role of integrase and reverse transcriptase in retroviral life cycle.
- important in the life cycle of HIV
- Integrase – splices viral DNA into host DNA to take “control” of the cell